Answer:
A; rough endoplasmic reticulum
Explanation:
The endoplasmic reticulum is the network of tubules and is present scattered in the cytoplasm. it is of two types: rough endoplasmic reticulum and smooth endoplasmic reticulum. The rough endoplasmic reticulum is continuous with the outer nuclear membrane and surrounds the nuclear envelop. The function of rough endoplasmic reticulum is to carry out protein synthesis as it has ribosomes studded on its surface.